function mmSpeak(textToSpeak) { 
    var u = new SpeechSynthesisUtterance();
    u.text = textToSpeak; 
     //汉语
    u.lang = 'zh-CN'; 
     //日语
     //u.lang = 'ja-JP';
      u.rate =1;  
      speechSynthesis.speak(u);
} 